First off there is no "idiocy" on your part. Stop thinking that way, we put ourselves down way too much! BPD and lying, good question. I would have to say because to a certain extent it has become a way of life. What I mean by that is when you hear people talk about being chameleons and changing into what ever they think will win them the most approval is a lie. A lot of people with BPD will also present with additional "symptoms" that they really don't have to feel like they need more attention than others. (probably upset some people there, but it's true) It can even be as basic as how many times have you down played how bad you really feel. Being honest, really honest, opens you up to rejection and hurt, something that is scary as hell for most people, but can truly be a horrifying thought to someone with BPD.